Active behavioral coping alters the behavioral but not the endocrine response to stress

Exposure to traumatic stressors typically causes lasting changes in emotionality and behavior. However, coping strategies have been shown to prevent and alleviate many stress consequences and the biological mechanisms that underlie coping are of great interest. Whereas the laboratory stressor inescapable tail-shock induces anxiety-like behaviors, here we demonstrate that permitting a rat to chew on a wooden dowel during administration of tail-shock prevented the development of anxiety like behaviors in the open field and juvenile social exploration tests. Uncontrollable stressors increase corticosterone and decrease thyroid hormone, and we hypothesized that coping would blunt these changes. While tail-shock did produce these effects, active coping did not alter hormone levels. The dissociation between behavioral resilience and circulating hormones is discussed with regard to the utility of these molecules as biomarkers for psychiatric disease.